I find for myself that my first thought is never my best thought. My first thought is always someone else’s; it’s always what I’ve already heard about the subject, always the conventional wisdom. It’s only by concentrating, sticking to the question, being patient, letting all the parts of my mind come into play, that I arrive at an original idea.

Effective thinking isn’t about ‘working hard’ in any brute or rote sense; it is about learning to spot, defend, nurture and grow our fleeting, tentative periods of insight.